Archive for the ‘general’ Category

Gilad gave a talk about Hopscotch last week at lang.net 09. In his blog post about it he modestly speaks in detail only about the talks of others, but since his is the first properly recorded demo of Hopscotch available online, I want to specially mention it here. It features the latest and the greatest version of the tools, so it’s even better than what could be seen at Smalltalk Solutions, WASDeTT and ECOOP last year.

Luis Diego Fallas has implemented a Twitter client using Newspeak and Hopscotch. Even after doing as much work in Hopscotch as I did, I’m very impressed to see a “real” program and not a developer tool within the familiar window. Thanks, Luis!

Just a few months ago I never would have thought I’d work on anything other than Newspeak for the foreseeable future. Working with Gilad, Peter, and others was a fantastic experience, and building a programming platform almost from scratch without political and marketing baggage attached was not a job you find every day on monster.com. But it turns out sometimes the foreseeable future runs out sooner than you expect.

The end of full-time Newspeak work is a sad thing, but I’m not writing this to cry over spilt milk. They say new beginnings bring new opportunities, and this is how I want to look at it. I have just finished my first week working for Google.

Michael Lucas-Smith posted an interesting summary of UI layout models. I tried to leave the following as a comment, but the blog server swallowed it without posting. Fortunately, I half-expected this and copied the text before submitting. I’m posting it here instead, with some further edits.

Overall, this is a good summary, but there is a very important model it misses.

The model is a variant of constrained-based layout called linear constraints. In that model widget positions are expressed as a system of linear equations. This more formalized approach, unlike “intuitive” models with springs, wires and other pseudo-real life accessories, isn’t fiddly at all. There are algorithms (Cassowary is the most famous) to efficiently solve such constraint systems.

Also, importantly, many other models: fixed, relative, stacked and grid layouts are special cases of linear constraints. Only flow cannot be expressed this way. Thus, the models are not all incompatible. Also note that I’m listing “relative” as an additional model, which is the correct way to describe the VW approach (first proposed, most likely, by Luca Cardelli). (“Fixed” would be the case when the widget’s bounds are expressed as coordinates in some coordinate system, usually relative to the containing widget’s top left corner).

I’m not sure what it means to say that layout should not be part of the widget framework proper, without first defining the proper. One extreme is Windows which provides no automatic layout capabilities at all. That is indeed the pure fixed model. The other are frameworks with container visuals. In those frameworks the specific layout model is indeed dictated by the container. But still, the only difference between the two is that something like Qt has containers that do layout and Windows doesn’t. In neither of them layout is part of widgets (by widgets I mean atomic leaf components such as buttons or list views).

The important question is how hard or easy it is to introduce new containers with different layout models, but it is a matter of the overall framework design. The main complication here are performance constraints. The framework should reasonably quickly respond to incremental layout changes, and reconciling that need with pluggability of containers and their layout policies is where the devil lies. I’d estimate about 70% (if not more) of Brazil design effort has had something to do with layout management.

I normally work on a Mac, but my “official” work laptop runs Windows (ok, it also has Linux on it) and I’ve been using it lately to be able to run Strongtalk. So I turn it on today and out of the blue pops up this message.

Two months ago I left Cincom, to reset and refresh a number of things in my work and life. For those few who might care, so far it’s been working out great. Neat things to write about come up like never before, and this looks like the perfect time for a new blog unaffiliated with any particular company or product.

Many thanks to Bob Westergaard for helping me brainstorm the idea of a sufficiently non-committal and yet vaguely relevant title. I like how 3 + 4 and the magical number 7 are related to my interest and involvement with languages and interfaces. They are the creations different and yet very much alike in being two of the many things that try and often fail to make us smart.